Thanks everyone for the replies :D
Actually I was first surprised by F360 behavior at corners, as indeed it's not what you would expect from subdivided polys, then I found it really useful and time saving in my workflow, so I was a little disappointed to not have that in this new MOI feature. So I guess I'll have to hope the clamped down option will be implemented some day ;)
Thanks for this amazing program Michael!

Hi marc, so for the next MoI v4 beta there will be an additional option under Options > Import/Export > SubD import options > "Open boundaries: Keep corners" or "Open boundaries: Rounded".

The default will be "Keep corners" since that seems to be more common than I had thought and it also actually makes a simpler result too. But you'll be able to set it to Open boundaries: Rounded which will then give the current version behavior.

- Michael

Hi Michael, thanks so much for this. It is really cool that you take it into consideration like that. :D

Hi Michael, I've just installed the latest beta, and I'm really grateful you implemented the option like you said, I can now skip Fusion 360 entirely, thanks again for this ! :D